Pasi B M, Carrier D R
Department of Biology, University of Utah, Salt Lake City, UT 84112, USA.
J Evol Biol. 2003 Mar;16(2):324-32. doi: 10.1046/j.1420-9101.2003.00512.x.
The physical demands of rapid and economical running differ from those of physical fighting such that functional trade-offs may prevent simultaneous evolution of optimal performance in both behaviours. Here we test three hypotheses of functional trade-off by measuring determinants of limb musculoskeletal function in two breeds of domestic dogs that have undergone intense artificial selection for running (Greyhound) or fighting performance (Pit Bull). We found that Greyhounds differ from Pit Bulls in having relatively less muscle mass distally in their limbs, weaker muscles in their forelimbs than their hindlimbs, and a much greater capacity for elastic storage in the in-series tendons of the extensor muscles of their ankle joints. These observations are consistent with the hypothesis that specialization for rapid or economical running can limit fighting performance and vice versa. We suggest that functional trade-offs that prevent simultaneous evolution of optimal performance in both locomotor and fighting abilities are widespread taxonomically.
快速且经济地奔跑对身体的要求与近身搏斗不同，以至于功能权衡可能会阻碍这两种行为的最佳表现同时进化。在此，我们通过测量两种经过强烈人工选择以提高奔跑能力（灵缇犬）或搏斗能力（比特犬）的家犬品种的肢体肌肉骨骼功能决定因素，来检验功能权衡的三个假设。我们发现，灵缇犬与比特犬的不同之处在于，其四肢远端的肌肉量相对较少，前肢肌肉比后肢肌肉弱，并且踝关节伸肌的串联肌腱中的弹性储存能力要强得多。这些观察结果与以下假设一致：专门化于快速或经济地奔跑会限制搏斗表现，反之亦然。我们认为，阻碍运动和搏斗能力的最佳表现同时进化的功能权衡在分类学上广泛存在。
